The role of human Metapneumovirus genetic diversity and nasopharyngeal viral load on symptom severity in adults

Abstract

BackgroundHuman metapneumovirus (HMPV) is established as one of the causative agents of respiratory tract infections. To date, there are limited reports that describe the effect of HMPV genotypes and/or viral load on disease pathogenesis in adults. This study aims to determine the role of HMPV genetic diversity and nasopharyngeal viral load on symptom severity in outpatient adults with acute respiratory tract infections.MethodsSeverity of common cold symptoms of patients from a teaching hospital was assessed by a four-category scale and summed to obtain the total symptom severity score (TSSS). Association between the fusion and glycoprotein genes diversity, viral load (quantified using an improved RT-qPCR assay), and symptom severity were analyzed using bivariate and linear regression analyses.ResultsAmong 81/3706 HMPV-positive patients, there were no significant differences in terms of demographics, number of days elapsed between symptom onset and clinic visit, respiratory symptoms manifestation and severity between different HMPV genotypes/sub-lineages. Surprisingly, elderly patients (≥65 years old) had lower severity of symptoms (indicated by TSSS) than young and middle age adults (p = 0.008). Nasopharyngeal viral load did not correlate with nor predict symptom severity of HMPV infection. Interestingly, at 3–5 days after symptom onset, genotype A-infected patients had higher viral load compared to genotype B (4.4 vs. 3.3 log10 RNA copies/μl) (p = 0.003).ConclusionsOverall, HMPV genetic diversity and viral load did not impact symptom severity in adults with acute respiratory tract infections. Differences in viral load dynamics over time between genotypes may have important implications on viral transmission.Electronic supplementary materialThe online version of this article (10.1186/s12985-018-1005-8) contains supplementary material, which is available to authorized users.

Human metapneumovirus as cause of severe community-acquired pneumonia in adults: insights from a ten-year molecular and epidemiological analysis

“…The low number of cases of the three different hMPV lineages, the presence of coinfections and the retrospective nature of the study made impossible to analyze the clinical pattern and the evolution of the patients based on the genotype of the infecting hMPV. However, to date, there are no significant differences in the evolution or clinical manifestation between different genotypes of HMPV in adults in the outpatient setting [30].…”

Genetic characterization of human metapneumovirus identified through community and facility‐based surveillance of infants in Dhaka, Bangladesh

“…The immunologic response to different serotypes of hMPV in the human host is yet to be known . In the hMPV literature, it is mainly a genetic diversity that has been considered as a risk factor for disease severity and a key area of consideration for vaccine development . Thus, an understanding of the local molecular epidemiology of hMPV is important for potential future vaccine selection and the prediction of vaccine effectiveness for the Bangladeshi population.…”

“…3 In the hMPV literature, it is mainly a genetic diversity that has been considered as a risk factor for disease severity and a key area of consideration for vaccine development. 16,17 Thus, an understanding of the local molecular epidemiology of hMPV is important for potential future vaccine selection and the prediction of vaccine effectiveness for the Bangladeshi population. In this study, we aimed to describe the epidemiology of hMPV infection and the genotypic diversity of hMPV strains circulating in Dhaka, Bangladesh.…”

Detection of multiple viral sequences in the respiratory tract samples of suspected Middle East respiratory syndrome coronavirus patients in Jakarta, Indonesia 2015–2016

“…In the present study, HMPV was detected from a nasal swab of a 71-year-old patient with pneumonia. HMPV is one of the most significant causes of upper and lower respiratory tract infections in children and the elderly, especially the immunocompromised and those with underlying respiratory conditions (Oong et al, 2018;Taniguchi et al, 2019;Jallow et al, 2019). Two genotypes of HMPV have been identified, which can be classified into five lineages, A1, A2a, A2b, B1, and B2.…”